Heart
Failure
Heart
failure, also called congestive heart failure,
is a condition in which the heart cannot pump
enough oxygenated blood to meet the needs of the
body's other organs. The heart keeps pumping,
but not as efficiently as a healthy heart. Usually,
the loss in the heart's pumping action is
a symptom of an underlying heart problem. Heart
failure affects nearly 5 million US adults. It
is on the rise with an estimated 400,000 to 700,000
new cases each year.
Heart
failure may result from any/all of the following:
- heart valve disease
- caused by past rheumatic fever or other infections
- high blood pressure
(hypertension)
- infections of the heart
valves and/or heart muscle (i.e., endocarditis)
- previous heart attack(s)
(myocardial infarction) - scar tissue from previous
attacks may interfere with the heart muscle's
ability to work normally
- coronary artery disease
- narrowed arteries that supply blood to the
heart muscle
- cardiomyopathy - or
another primary disease of the heart muscle
- congenital heart disease/defects
(present at birth)
- cardiac arrhythmias
(irregular heartbeats)
- chronic lung disease
and pulmonary embolism
- drug-induced heart
failure
- excessive sodium intake
- hemorrhage and anemia
- diabetes
Heart
failure interferes with the kidney's normal
function of eliminating excess sodium and waste
from the body. In congestive heart failure, the
body retains more fluid - resulting in swelling
of the ankles and legs. Fluid also collects in
the lungs - resulting in shortness of breath.
The
following are the most common symptoms of heart
failure. However, each individual may experience
symptoms differently. Symptoms may include:
- shortness of breath
during rest, exercise, or lying flat
- weight gain
- visible swelling of
the legs and ankles (due to a build-up of fluid),
and, occasionally, the abdomen
- fatigue and weakness
- loss of appetite and
nausea
- persistent cough -
often produces mucus or blood-tinged sputum
- reduced urination
The
severity of the condition and symptoms depends
on how much of the heart's pumping capacity
has been lost.
The
symptoms of heart failure may resemble other conditions
or medical problems. Always consult your physician
for a diagnosis.
In addition
to a complete medical history and physical examination,
diagnostic procedures for heart failure may include
any, or a combination of, the following:
- chest x-ray - a diagnostic
test which uses invisible electromagnetic energy
beams to produce images of internal tissues,
bones, and organs onto film.
- echocardiogram (Also
called echo.) - a noninvasive test that uses
sound waves to produce a study of the motion
of the heart's chambers and valves. The
echo sound waves create an image on the monitor
as an ultrasound transducer is passed over the
heart.
- electrocardiogram
(ECG or EKG) - a test that records the electrical
activity of the heart, shows abnormal rhythms
(arrhythmias or dysrhythmias), and detects heart
muscle damage.
- BNP testing - B-type
natriuretic peptide (BNP) is a hormone released
from the ventricles in response to increased
wall tension (stress) that occurs with heart
failure. BNP levels rise as wall stress increases.
BNP levels are useful in the rapid evaluation
of heart failure.
Specific
treatment for heart failure will be determined
by your physician based on:
- your age, overall health,
and medical history
- extent of the disease
- your tolerance for
specific medications, procedures, or therapies
- expectations for the
course of the disease
- your opinion or preference
The
cause of the heart failure will dictate the treatment
protocol established. If the heart failure is
caused by a valve disorder, then surgery is usually
performed. If the heart failure is caused by a
disease, such as anemia, then the disease is treated.
And, although there is no cure for heart failure
due to a damaged heart muscle, many forms of treatment
have proven to be successful.
The
goal of treatment is to improve a person's
quality of life by making the appropriate lifestyle
changes and implementing drug therapy.
Treatment
of heart failure may include:
- controlling risk factors
- losing weight (if
overweight)
- restricting salt
and fat from the diet
- stop smoking
- abstaining from
alcohol
- proper rest
- controlling blood
sugar if diabetic
- medication, such as:
- angiotensin converting
enzyme (ACE) inhibitors - to
decrease the pressure inside the blood vessels,
or angiotensin II receptor blockers if ACE
inhibitors are not tolerated
- diuretics -
to reduce the amount of fluid in the body
- vasodilators -
to dilate the blood vessels and reduce workload
on the heart
- digitalis -
to increase heart strength and control rhythm
problems
- inotropes -
increase the pumping action of the heart
- antiarrhythmia
medications - keep the rhythm
regular and prevent sudden cardiac death
- beta-blockers
- reduce the heart's tendency
to beat faster by blocking specific receptors
on the cells that make up the heart
- aldosterone blockers
- block the effects of aldosterone
which causes sodium and water retention
- biventricular pacing/cardiac
resynchronization therapy - a new type of pacemaker
that paces both sides of the heart simultaneously
to coordinate contractions and improve pumping
ability. Heart failure patients are potential
candidates for this therapy
- implantable cardioverter
defibrillator - a device similar to a pacemaker
that senses when the heart is beating too fast
and delivers an electrical shock to convert
the fast rhythm to a normal rhythm
- heart transplantation
A ventricular
assist device (VAD) is a mechanical device that
is used to take over the pumping function for
one or both of the heart’s ventricles. A
VAD may be necessary when heart failure progresses
to the point that medications and other treatments
are no longer effective.
For
persons with severe or end-stage heart failure,
ventricular assist devices (VADs) may be required
to support the heart in order to ensure an adequate
cardiac output (amount of blood pumped out by
the heart per minute) to meet the body’s
needs.
Heart
transplantation is an option for some patients
with severe heart failure (HF), but during this
late stage of HF, over 50 percent of persons
on a waiting list for heart transplantation will
die before receiving a donor heart. Organ donors
are in short supply and do not meet the demand
for patients waiting for heart transplant. The
wait time for heart transplantation may often
exceed 200 days.
Long
wait times and decreased availability of donors
strengthens the need to seek other methods to
support the failing heart. Patients may die waiting
for a transplant or important organs such as the
liver and kidney may become permanently damaged
before a donor heart is available. VADs have shown
great promise in maintaining adequate blood circulation
in cases of severe HF.
VADs
may be used for the following situations:
- bridge to transplant
- implantation of a VAD to support the patient
with end-stage HF who is waiting for heart transplantation.
- bridge to recovery
- implantation of a VAD to support the patient
with potentially reversible HF. Once the heart
has recovered sufficiently, the VAD may be removed.
- destination therapy
- implantation of a VAD to support the patient
with end-stage HF who is not a candidate for
heart transplantation. A portable VAD may be
used in this situation so that the patient may
be discharged from the hospital and return home.
Some
VADs are designed to support the right heart alone
(right ventricular assist device, or RVAD) or
both ventricles (biventricular assist device,
or BiVAD), but commonly the left ventricle (left
ventricular support device, or LVAD) is the primary
point of support.
VADs
are most commonly implanted during an open heart
surgical procedure.
All
types of VADs have similar complications postoperatively
and during prolonged therapy:
- infection
Infection is a serious complication that occurs
frequently. Patients in general are vulnerable
to postoperative infections such as intravenous
(IV) line infections, pneumonia, and urinary
tact infections. The patient receiving a VAD
is at even greater risk due in part to the patient's
weakened state. VAD-related infections may occur
at the skin connections of the pump and tubing,
in the heart (endocarditis), or in the blood
stream (sepsis).
To avoid infections,
all cannula (tubing) exit sites must be dressed
daily using sterile technique, the exit cannulas
must be secured to prevent tension and pulling
on the skin, and the skin around all exit
sites must be completely healed before extensive
activity is allowed.
- bleeding
Bleeding is common in the immediate postoperative
period due to cardiopulmonary (heart-lung) bypass
time, anticoagulation (prevention of blood clotting
with medication), and long surgical procedures.
Additionally, liver dysfunction (which may be
present preoperatively) and previous heart surgeries
increase the patient's risk for bleeding.
Blood transfusions may be required for major
bleeding, but are avoided if possible.
- right ventricular
failure
Right ventricular failure is a concern in patients
who have high pressures in the lung circulation
before implant. Medications can help support
the right ventricle during the initial period
of recovery until the pump begins to improve
the cardiac output.
- thromboembolism (blood
clot)
Thromboembolism (blood clot) may cause strokes.
All VADs have a risk of clot formation because
blood comes in contact with the surfaces of
the pump and cannulas. Almost all VADs require
some form of anticoagulation such as Coumadin
to reduce the risk of stroke. These medications
may put the patient at greater risk for bleeding,
however, and should be closely monitored.
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